Mutations in plasticity-related-gene-1 (PRG-1) protein contribute to hippocampal seizure susceptibility and modify epileptic phenotype.

The Phospholipid Phosphatase Related 4 gene (PLPPR4,  *607813) encodes the Plasticity-Related-Gene-1 (PRG-1) protein. This cerebral synaptic transmembrane-protein modulates cortical excitatory transmission on glutamatergic neurons. In mice, homozygous Prg-1 deficiency causes juvenile epilepsy. Its epileptogenic potential in humans was unknown. Thus, we screened 18 patients with infantile epileptic spasms syndrome (IESS) and 98 patients with benign familial neonatal/infantile seizures (BFNS/BFIS) for the presence of PLPPR4 variants. A girl with IESS had inherited a PLPPR4-mutation (c.896C > G, NM_014839; p.T299S) from her father and an SCN1A-mutation from her mother (c.1622A > G, NM_006920; p.N541S). The PLPPR4-mutation was located in the third extracellular lysophosphatidic acid-interacting domain and in-utero electroporation (IUE) of the Prg-1p.T300S construct into neurons of Prg-1 knockout embryos demonstrated its inability to rescue the electrophysiological knockout phenotype. Electrophysiology on the recombinant SCN1Ap.N541S channel revealed partial loss-of-function. Another PLPPR4 variant (c.1034C > G, NM_014839; p.R345T) that was shown to result in a loss-of-function aggravated a BFNS/BFIS phenotype and also failed to suppress glutamatergic neurotransmission after IUE. The aggravating effect of Plppr4-haploinsufficiency on epileptogenesis was further verified using the kainate-model of epilepsy: double heterozygous Plppr4-/+|Scn1awt|p.R1648H mice exhibited higher seizure susceptibility than either wild-type, Plppr4-/+, or Scn1awt|p.R1648H littermates. Our study shows that a heterozygous PLPPR4 loss-of-function mutation may have a modifying effect on BFNS/BFIS and on SCN1A-related epilepsy in mice and humans.

Update of penetrance estimates in Birt-Hogg-Dubé syndrome.

BACKGROUND: Birt-Hogg-Dubé (BHD) syndrome is a rare genetic syndrome caused by pathogenic or likely pathogenic germline variants in the FLCN gene. Patients with BHD syndrome have an increased risk of fibrofolliculomas, pulmonary cysts, pneumothorax and renal cell carcinoma. There is debate regarding whether colonic polyps should be added to the criteria. Previous risk estimates have mostly been based on small clinical case series. METHODS: A comprehensive review was conducted to identify studies that had recruited families carrying pathogenic or likely pathogenic variants in FLCN. Pedigree data were requested from these studies and pooled. Segregation analysis was used to estimate the cumulative risk of each manifestation for carriers of FLCN pathogenic variants. RESULTS: Our final dataset contained 204 families that were informative for at least one manifestation of BHD (67 families informative for skin manifestations, 63 for lung, 88 for renal carcinoma and 29 for polyps). By age 70 years, male carriers of the FLCN variant have an estimated 19% (95% CI 12% to 31%) risk of renal tumours, 87% (95% CI 80% to 92%) of lung involvement and 87% (95% CI 78% to 93%) of skin lesions, while female carriers had an estimated 21% (95% CI 13% to 32%) risk of renal tumours, 82% (95% CI 73% to 88%) of lung involvement and 78% (95% CI 67% to 85%) of skin lesions. The cumulative risk of colonic polyps by age 70 years old was 21% (95% CI 8% to 45%) for male carriers and 32% (95% CI 16% to 53%) for female carriers. CONCLUSIONS: These updated penetrance estimates, based on a large number of families, are important for the genetic counselling and clinical management of BHD syndrome.

Birt-Hogg-Dubé-Syndrom: ein zu selten diagnostiziertes erbliches Tumorsyndrom.

Das Birt-Hogg-Dubé-Syndrom (BHD-Syndrom, eigentlich Hornstein-Knickenberg- Syndrom) ist ein autosomal dominant erbliches Tumorsyndrom, welches durch Mutationen im FLCN-Gen auf Chromosom 17 verursacht wird. Patienten mit BHD-Syndrom können altersabhängig verschiedene Symptome zeigen, deren Ausprägung auch innerhalb einer Familie unterschiedlich schwer sein kann. Ein frühes Symptom sind basal betonte Lungenzysten, welche Ursache wiederholter Spontanpneumothoraces sein können. Die Mehrheit der Patienten (> 90 %) entwickelt im mittleren Lebensalter zahlreiche Fibrofollikulome vor allem im Gesicht und am Oberkörper. Für die Prognose entscheidend ist eine gezielte Tumorvorsorge, da ein Lebenszeitrisiko von 12-34 % für benigne und maligne Nierentumoren besteht. Die Nierentumoren beim BHD-Syndrom können verschiedenen histologischen Subgruppen angehören, wobei multifokale, auch bilaterale Hybridtumoren mit chromophoben und onkozytären Anteilen häufig sind. Die frühzeitige Diagnosestellung ebenso wie die langfristige Betreuung von Familien mit BHD-Syndrom erfordern eine interdisziplinäre Zusammenarbeit.

Birt-Hogg-Dubé syndrome: an underdiagnosed genetic tumor syndrome.

Birt-Hogg-Dubé syndrome (BHD, also referred to as Hornstein-Knickenberg syndrome) is an autosomal dominant tumor syndrome caused by mutations in the FLCN gene located on chromosome 17. Depending on their age, patients with BHD may exhibit various clinical signs and symptoms. Disease severity can vary greatly among members of the same family. Early symptoms include basal lung cysts, which can lead to recurrent spontaneous pneumothoraces. The majority of patients (> 90 %) develop multiple fibrofolliculomas, especially on the face and upper trunk, in the second or third decade of life. Given the 12-34 % lifetime risk of developing benign or malignant renal tumors, targeted screening programs are prognostically crucial. While these renal tumors may belong to various histological subtypes, common variants include multifocal - sometimes bilateral - chromophobe and oncocytic hybrid tumors. Early diagnosis and adequate long-term care of families with BHD require interdisciplinary cooperation.

Cellular and extracellular miRNAs are blood-compartment-specific diagnostic targets in sepsis.

Septic shock is a common medical condition with a mortality approaching 50% where early diagnosis and treatment are of particular importance for patient survival. Novel biomarkers that serve as prompt indicators of sepsis are urgently needed. High-throughput technologies assessing circulating microRNAs represent an important tool for biomarker identification, but the blood-compartment specificity of these miRNAs has not yet been investigated. We characterized miRNA profiles from serum exosomes, total serum and blood cells (leukocytes, erythrocytes, platelets) of sepsis patients by next-generation sequencing and RT-qPCR (n = 3 × 22) and established differences in miRNA expression between blood compartments. In silico analysis was used to identify compartment-specific signalling functions of differentially regulated miRNAs in sepsis-relevant pathways. In septic shock, a total of 77 and 103 miRNAs were down- and up-regulated, respectively. A majority of these regulated miRNAs (14 in serum, 32 in exosomes and 73 in blood cells) had not been previously associated with sepsis. We found a distinctly compartment-specific regulation of miRNAs between sepsis patients and healthy volunteers. Blood cellular miR-199b-5p was identified as a potential early indicator for sepsis and septic shock. miR-125b-5p and miR-26b-5p were uniquely regulated in exosomes and serum, respectively, while one miRNA (miR-27b-3p) was present in all three compartments. The expression of sepsis-associated miRNAs is compartment-specific. Exosome-derived miRNAs contribute significant information regarding sepsis diagnosis and survival prediction and could serve as newly identified targets for the development of novel sepsis biomarkers.

Nocturnal frontal lobe epilepsy caused by a mutation in the GATOR1 complex gene NPRL3.

Mutations in NPRL3, one of three genes that encode proteins of the mTORC1-regulating GATOR1 complex, have recently been reported to cause cortical dysplasia with focal epilepsy. We have now analyzed a multiplex epilepsy family by whole exome sequencing and identified a frameshift mutation (NM_001077350.2; c.1522delG; p.E508Rfs*46) within exon 13 of NPRL3. This truncating mutation causes an epilepsy phenotype characterized by early childhood onset of mainly nocturnal frontal lobe epilepsy. The penetrance in our family was low (three affected out of six mutation carriers), compared to families with either ion channel- or DEPDC5-associated familial nocturnal frontal lobe epilepsy. The absence of apparent structural brain abnormalities suggests that mutations in NPRL3 are not necessarily associated with focal cortical dysplasia but might be able to cause epilepsy by different, yet unknown pathomechanisms.

Distinct nuclear orientation patterns for mouse chromosome 11 in normal B lymphocytes.

BACKGROUND: Characterizing the nuclear orientation of chromosomes in the three-dimensional (3D) nucleus by multicolor banding (mBANDing) is a new approach towards understanding nuclear organization of chromosome territories. An mBANDing paint is composed of multiple overlapping subchromosomal probes that represent different regions of a single chromosome. In this study, we used it for the analysis of chromosome orientation in 3D interphase nuclei. We determined whether the nuclear orientation of the two chromosome 11 homologs was random or preferential, and if it was conserved between diploid mouse Pre B lymphocytes of BALB/c origin and primary B lymphocytes of congenic [T38HxBALB/c]N wild-type mice. The chromosome orientation was assessed visually and through a semi-automated quantitative analysis of the radial and angular orientation patterns observed in both B cell types. RESULTS: Our data indicate that there are different preferential patterns of chromosome 11 orientation, which are not significantly different between both mouse cell types (p > 0.05). In the most common case for both cell types, both copies of chromosome 11 were oriented in parallel with the nuclear border. The second most common pattern in both types of B lymphocytes was with one homolog of chromosome 11 positioned with its telomeric end towards the nuclear center and with its centromeric end towards the periphery, while the other chromosome 11 was found parallel with the nuclear border. In addition to these two most common orientations present in approximately 50% of nuclei from each cell type, other orientations were observed at lower frequencies. CONCLUSIONS: We conclude that there are probabilistic, non-random orientation patterns for mouse chromosome 11 in the mouse B lymphocytes we investigated (p < 0.0001).

Hexosamine biosynthetic pathway mutations cause neuromuscular transmission defect.

Neuromuscular junctions (NMJs) are synapses that transmit impulses from motor neurons to skeletal muscle fibers leading to muscle contraction. Study of hereditary disorders of neuromuscular transmission, termed congenital myasthenic syndromes (CMS), has helped elucidate fundamental processes influencing development and function of the nerve-muscle synapse. Using genetic linkage, we find 18 different biallelic mutations in the gene encoding glutamine-fructose-6-phosphate transaminase 1 (GFPT1) in 13 unrelated families with an autosomal recessive CMS. Consistent with these data, downregulation of the GFPT1 ortholog gfpt1 in zebrafish embryos altered muscle fiber morphology and impaired neuromuscular junction development. GFPT1 is the key enzyme of the hexosamine pathway yielding the amino sugar UDP-N-acetylglucosamine, an essential substrate for protein glycosylation. Our findings provide further impetus to study the glycobiology of NMJ and synapses in general.

Calcium signaling and epilepsy.

Calcium signaling is involved in a multitude of physiological and pathophysiological mechanisms. Over the last decade, it has been increasingly recognized as an important factor in epileptogenesis, and it is becoming obvious that the excess synchronization of neurons that is characteristic for seizures can be linked to various calcium signaling pathways. These include immediate effects on membrane excitability by calcium influx through ion channels as well as delayed mechanisms that act through G-protein coupled pathways. Calcium signaling is able to cause hyperexcitability either by direct modulation of neuronal activity or indirectly through calcium-dependent gliotransmission. Furthermore, feedback mechanisms between mitochondrial calcium signaling and reactive oxygen species are able to cause neuronal cell death and seizures. Unravelling the complexity of calcium signaling in epileptogenesis is a daunting task, but it includes the promise to uncover formerly unknown targets for the development of new antiepileptic drugs.

Identification of microRNA biomarkers simultaneously expressed in circulating extracellular vesicles and atherosclerotic plaques.

Background: Atherosclerosis is a widespread disorder of the cardiovascular system. The early detection of plaques by circulating biomarkers is highly clinically relevant to prevent the occurrence of major complications such as stroke or heart attacks. It is known that extracellular vesicles (EVs) are important in intercellular communication in atherosclerotic disorders and carry many components of their cells of origin, including microRNAs (miRNAs). In this study, we test the assumption that miRNAs present in material acquired from plaques in patients undergoing surgery for atherosclerotic carotid artery stenosis are also expressed in circulating EVs obtained from the identical patients. This would allow the adoption of a liquid biopsy approach for the detection of plaques. Methods: We studied 22 surgical patients with atherosclerotic carotid arterial stenosis and 28 healthy controls. EVs were isolated from serum by precipitation. miRNA expression profiles of serum-derived EVs were obtained by small RNA sequencing and in plaque material simultaneously acquired from patients. A comparative analysis was performed to identify circulating atherosclerosis-associated miRNAs that are also detectable in plaques. Results: Seven miRNAs were found to be differentially regulated in patient serum compared with the serum of healthy controls. Of these, miR-193b-5p, miR-193a-5p, and miR-125a-3p were significantly upregulated in patients compared with that in healthy controls and present in both, circulating EVs and plaque material. An overrepresentation analysis of experimentally validated mRNA targets revealed an increased regulation of inflammation and vascular growth factors, key players in atherosclerosis and plaque formation. Conclusion: Our findings suggest that circulating EVs reflect plaque development in patients with symptomatic carotid artery stenosis, which can serve as biomarker candidates for detecting the presence of atherosclerotic plaques.

Extracellular vesicles secreted by 3D tumor organoids are enriched for immune regulatory signaling biomolecules compared to conventional 2D glioblastoma cell systems.

Background: Newer 3D culturing approaches are a promising way to better mimic the in vivo tumor microenvironment and to study the interactions between the heterogeneous cell populations of glioblastoma multiforme. Like many other tumors, glioblastoma uses extracellular vesicles as an intercellular communication system to prepare surrounding tissue for invasive tumor growth. However, little is known about the effects of 3D culture on extracellular vesicles. The aim of this study was to comprehensively characterize extracellular vesicles in 3D organoid models and compare them to conventional 2D cell culture systems. Methods: Primary glioblastoma cells were cultured as 2D and 3D organoid models. Extracellular vesicles were obtained by precipitation and immunoaffinity, with the latter allowing targeted isolation of the CD9/CD63/CD81 vesicle subpopulation. Comprehensive vesicle characterization was performed and miRNA expression profiles were generated by smallRNA-sequencing. In silico analysis of differentially regulated miRNAs was performed to identify mRNA targets and corresponding signaling pathways. The tumor cell media and extracellular vesicle proteome were analyzed by high-resolution mass spectrometry. Results: We observed an increased concentration of extracellular vesicles in 3D organoid cultures. Differential gene expression analysis further revealed the regulation of twelve miRNAs in 3D tumor organoid cultures (with nine miRNAs down and three miRNAs upregulated). MiR-23a-3p, known to be involved in glioblastoma invasion, was significantly increased in 3D. MiR-7-5p, which counteracts glioblastoma malignancy, was significantly decreased. Moreover, we identified four miRNAs (miR-323a-3p, miR-382-5p, miR-370-3p, miR-134-5p) located within the DLK1-DIO3 domain, a cancer-associated genomic region, suggesting a possible importance of this region in glioblastoma progression. Overrepresentation analysis identified alterations of extracellular vesicle cargo in 3D organoids, including representation of several miRNA targets and proteins primarily implicated in the immune response. Conclusion: Our results show that 3D glioblastoma organoid models secrete extracellular vesicles with an altered cargo compared to corresponding conventional 2D cultures. Extracellular vesicles from 3D cultures were found to contain signaling molecules associated with the immune regulatory signaling pathways and as such could potentially change the surrounding microenvironment towards tumor progression and immunosuppressive conditions. These findings suggest the use of 3D glioblastoma models for further clinical biomarker studies as well as investigation of new therapeutic options.

Risk of pneumothorax in Birt-Hogg-Dubé syndrome during pregnancy and birth.

Birt-Hogg-Dubé syndrome (BHDS) is a genetic disorder characterized by fibrofolliculomas, renal cell cancer and lung cysts. Patients are at risk to develop pneumothorax but the magnitude of this risk during pregnancy is unknown. Information was obtained from 46 women with BHDS that had at least one pregnancy (BHDS-with preg), 18 female BHDS relatives without pregnancies (BHDS-no preg) and 25 non-BHDS female relatives with at least one pregnancy (noBHDS-with preg). In total, 77 pneumothoraces occurred in the BHDS-with preg group (mean 1.7/patient) and 11 in the BHDS-no preg group. Comparison of patient years for the first two groups showed pneumothorax incidence rates of 0.054 and 0.016, respectively. The incidence rate difference was significant [0.038 (CI 0.02-0.057), value of p-value 0.0001]. This difference is not caused by an increased number of patients with pneumothorax but by an increased number of pneumothoraces per patient. Pregnancy in BHDS therefore might be a risk factor for multiple pneumothoraces.

Anesthetic­specific lncRNA and mRNA profile changes in blood during colorectal cancer resection: A prospective, matched­case pilot study.

Prometastatic and antitumor effects of different anesthetics have been previously analyzed in several studies with conflicting results. Thus, the underlying perioperative molecular mechanisms mediated by anesthetics potentially affecting tumor phenotype and metastasis remain unclear. It was hypothesized that anesthetic­specific long non­coding RNA (lncRNA) expression changes are induced in the blood circulation and play a crucial role in tumor outcome. In the present study, high­throughput sequencing and quantitative PCR were performed in order to identify lncRNA and mRNA expression changes affected by two therapeutic regimes, total intravenous anesthesia (TIVA) and volatile anesthetic gas (VAG) in patients undergoing colorectal cancer (CRC) resection. Total blood RNA was isolated prior to and following resection and characterized using RNA sequencing. mRNA­lncRNA interactions and their roles in cancer­related signaling of differentially expressed lncRNAs were identified using bioinformatics analyses. The comparison of these two time points revealed 35 differentially expressed lncRNAs in the TIVA­group, and 25 in the VAG­group, whereas eight were shared by both groups. Two lncRNAs in the TIVA­group, and 23 in the VAG­group of in silico identified target­mRNAs were confirmed as differentially regulated in the NGS dataset of the present study. Pathway analysis was performed and cancer relevant canonical pathways for TIVA were identified. Target­mRNA analysis of VAG revealed a markedly worsened immunological response against cancer. In this proof­of­concept study, anesthesic­specific expression changes in lncRNA and mRNA profiles in blood were successfully identified. Moreover, the data of the present study provide the first evidence that anesthesia­induced lncRNA pattern changes may contribute further in the observed differences in CRC outcome following tumor resection.

Delayed diagnosis of Birt-Hogg-Dubé syndrome might be aggravated by gender bias.

Background: Birt-Hogg-Dubé syndrome is a rare genetic tumor syndrome characterized by renal cell cancer, lung bullae, pneumothorax, and fibrofolliculoma. Patients with such orphan tumor disorders are at risk of not receiving a timely diagnosis. In the present, gender-sensitive study, we analyzed the delay between onset of symptoms and diagnosis of Birt-Hogg-Dubé syndrome. Methods: Clinical data of 158 patients from 91 unrelated families were collected. FLCN mutation testing was performed in index patients and family members. Findings: The occurrence of the first symptom (fibrofolliculoma, pneumothorax or renal cell cancer) was rarely followed by a timely diagnosis of Birt-Hogg-Dubé syndrome and did so significantly less often in female (1.3%) compared to male (11.4%) patients (chi-square 6.83, p-value 0.009). Only 17 out of 39 renal cell cancers (7/17 female, 10/22 male patients) were promptly recognized as a symptom of Birt-Hogg-Dubé syndrome. Patients in which renal cell cancer was initially not recognized as a symptom of Birt-Hogg-Dubé syndrome waited 9.7 years (females SD 9.2, range 1-29) and 8.8 years (males, SD 4.1, range 2-11) for their diagnosis, respectively. Four (three female, one male) patients developed renal cell cancer twice before the genetic tumor syndrome was diagnosed. The delay between fibrofolliculoma or pneumothorax as a first symptom and diagnosis of Birt-Hogg-Dubé syndrome was considerable but not significantly different between females and males (18.1/17.19 versus 16.1/18.92 years). Furthermore, 73 patients were only diagnosed due to family history (delay 15.1 years in females and 17.4 years in males). Interpretation: The delay between onset of symptoms and diagnosis of Birt-Hogg-Dubé syndrome can be substantial and gender-dependent, causing considerable health risks for patients and their families. It is therefore important to create more awareness of Birt-Hogg-Dubé syndrome and resolve gender biases in diagnostic work-up. Funding: None declared.

Seventh BHD international symposium: recent scientific and clinical advancement.

The 7th Birt-Hogg-Dubé (BHD) International Symposium convened virtually in October 2021. The meeting attracted more than 200 participants internationally and highlighted recent findings in a variety of areas, including genetic insight and molecular understanding of BHD syndrome, structure and function of the tumor suppressor Folliculin (FLCN), therapeutic and clinical advances as well as patients' experiences living with this malady.

Temperature and pharmacological rescue of a folding-defective, dominant-negative KV 7.2 mutation associated with neonatal seizures.

Benign familial neonatal seizures (BFNS) are a dominant epilepsy syndrome caused by mutations in the voltage-gated potassium channels K(V) 7.2 and K(V) 7.3. We examined the molecular pathomechanism of a BFNS-causing mutation (p.N258S) in the extracellular S5-H5 loop of K(V) 7.2. Wild type (WT) and mutant channels, expressed in both Xenopus laevis oocytes and CHO cells, were studied using electrophysiological techniques. The results revealed a pronounced loss-of-function with a dominant-negative effect of the mutant on WT K(V) 7.2 and K(V) 7.3 channels. Since single-channel recordings of K(V) 7.3-K(V) 7.2 and K(V) 7.3-N285S concatemers showed similar properties for both constructs, we hypothesized that the observed reduction in current amplitude was due to a folding and trafficking defect, which was confirmed by biochemical and immunocytochemical experiments revealing a reduced number of mutant channels in the surface membrane. Furthermore, rescuing experiments revealed that upon specific incubation of transfected CHO cells-either at lower temperatures of <30°C or in presence of the agonist retigabine (RTG)-the N258S-derived currents increased fivefold in contrast to the WT. The obtained results represent a first example of temperature and pharmacological rescue of a K(V) 7 mutation and suggest a folding and trafficking deficiency as the cause of reduced current amplitudes with a dominant-negative effect of N258S mutant proteins.

Mutations in FKBP10 can cause a severe form of isolated Osteogenesis imperfecta.

BACKGROUND: Mutations in the FKBP10 gene were first described in patients with Osteogenesis imperfecta type III. Two follow up reports found FKBP10 mutations to be associated with Bruck syndrome type 1, a rare disorder characterized by congenital contractures and bone fragility. This raised the question if the patients in the first report indeed had isolated Osteogenesis imperfecta or if Bruck syndrome would have been the better diagnosis. METHODS: The patients described here are affected by severe autosomal recessive Osteogenesis imperfecta without contractures. RESULTS: Homozygosity mapping identified FKBP10 as a candidate gene, and sequencing revealed a base pair exchange that causes a C-terminal premature stop codon in this gene. CONCLUSIONS: Our study demonstrates that FKBP10 mutations not only cause Bruck syndrome or Osteogenesis imperfecta type III but can result in a severe type of isolated Osteogenesis imperfecta type IV with prenatal onset. Furthermore, it adds dentinogenesis imperfecta to the spectrum of clinical symptoms associated with FKBP10 mutations.

Colorectal cancer risk in families with Birt-Hogg-Dubé syndrome increased.

OBJECTIVE: Birt-Hogg-Dubé syndrome (BHDS) is an inherited tumour syndrome characterised by three major symptoms: lung cysts with spontaneous pneumothorax, fibrofolliculoma and renal cell cancer. The first family with this syndrome was described in 1975 and one of its members presented with adenomatous colon polyps and colorectal cancer. Since then, it has been a matter of debate whether colorectal cancer is indeed part of the BHDS spectrum and if regular screening should be recommended. DESIGN: We analysed the frequency of colorectal cancer in a large sample of BHDS families. Clinical data were available from 256 BHDS patients (male 130, female 126) belonging to 83 unrelated families. For controls, 83 index patients who attended our outpatient clinic for non-malignancy-related genetic counselling and their family members (total of 519 controls) were used. RESULTS: The patients with BHDS showed a moderately but significantly increased rate of colorectal cancer (5.1% versus 1.5%, p-value .0068). Unexpectedly, 35% of patients with colorectal cancer corresponding to eight of 82 BHDS families fulfilled the revised Bethesda criteria for HNPCC, either because colorectal cancer occurred before age 50 years or because three family members were affected by colorectal cancer. Apart from colorectal cancer, no other HNPCC-associated tumours occurred within the Bethesda criteria-positive families, an observation that argues against a concurrence of BHDS and HNPCC in these families. CONCLUSION: The results suggest that BHDS is associated with early-onset colorectal cancer, a hypothesis that might have a marked impact on preventive screening recommendations.

Progranulin signaling in sepsis, community-acquired bacterial pneumonia and COVID-19: a comparative, observational study.

BACKGROUND: Progranulin is a widely expressed pleiotropic growth factor with a central regulatory effect during the early immune response in sepsis. Progranulin signaling has not been systematically studied and compared between sepsis, community-acquired pneumonia (CAP), COVID-19 pneumonia and a sterile systemic inflammatory response (SIRS). We delineated molecular networks of progranulin signaling by next-generation sequencing (NGS), determined progranulin plasma concentrations and quantified the diagnostic performance of progranulin to differentiate between the above-mentioned disorders using the established biomarkers procalcitonin (PCT), interleukin-6 (IL-6) and C-reactive protein (CRP) for comparison. METHODS: The diagnostic performance of progranulin was operationalized by calculating AUC and ROC statistics for progranulin and established biomarkers in 241 patients with sepsis, 182 patients with SIRS, 53 patients with CAP, 22 patients with COVID-19 pneumonia and 53 healthy volunteers. miRNAs and mRNAs in blood cells from sepsis patients (n = 7) were characterized by NGS and validated by RT-qPCR in an independent cohort (n = 39) to identify canonical gene networks associated with upregulated progranulin at sepsis onset. RESULTS: Plasma concentrations of progranulin (ELISA) in patients with sepsis were 57.5 (42.8-84.9, Q25-Q75) ng/ml and significantly higher than in CAP (38.0, 33.5-41.0 ng/ml, p < 0.001), SIRS (29.0, 25.0-35.0 ng/ml, p < 0.001) and the healthy state (28.7, 25.5-31.7 ng/ml, p < 0.001). Patients with COVID-19 had significantly higher progranulin concentrations than patients with CAP (67.6, 56.6-96.0 vs. 38.0, 33.5-41.0 ng/ml, p < 0.001). The diagnostic performance of progranulin for the differentiation between sepsis vs. SIRS (n = 423) was comparable to that of procalcitonin. AUC was 0.90 (95% CI = 0.87-0.93) for progranulin and 0.92 (CI = 0.88-0.96, p = 0.323) for procalcitonin. Progranulin showed high discriminative power to differentiate bacterial CAP from COVID-19 (sensitivity 0.91, specificity 0.94, AUC 0.91 (CI = 0.8-1.0) and performed significantly better than PCT, IL-6 and CRP. NGS and partial RT-qPCR confirmation revealed a transcriptomic network of immune cells with upregulated progranulin and sortilin transcripts as well as toll-like-receptor 4 and tumor-protein 53, regulated by miR-16 and others. CONCLUSIONS: Progranulin signaling is elevated during the early antimicrobial response in sepsis and differs significantly between sepsis, CAP, COVID-19 and SIRS. This suggests that progranulin may serve as a novel indicator for the differentiation between these disorders. TRIAL REGISTRATION: Clinicaltrials.gov registration number NCT03280576 Registered November 19, 2015.

Nicotinic receptor channelopathies and epilepsy.

Characterized by sudden episodes called seizures, epilepsy was recognized long ago as a neurological disorder that can have multiple forms ranging from benign to life threatening depending upon its severity. Although several evidences indicated that genes play an important role in at least half of the patients, it is only with the advances in molecular biology and genetics that the puzzle about oligogenic and monogenic epilepsies slowly starts to unfold. The finding of an association between a monogenic form of epilepsy and a mutation in the gene encoding the neuronal nicotinic acetylcholine receptor subunit CHRNA4 marked, in 1995, a turning point in our understanding of epilepsy. It also marked the first step towards the today widely acknowledged concept of epilepsies as channelopathies. Several mutations in nicotinic acetylcholine receptor genes have, since then, been identified, and the functional properties of these mutated receptors were characterized. In this work, we review, in the light of the latest discoveries, the effects caused by the mutations on the physiological properties of the receptors and the impact of such mutations on neuronal network functions.